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Fitting an Origin-Displaced Logarithmic Spiral
to Empirical Data by Differential Evolution Method
of Global Optimization
-- S K Mishra
Logarithmic spirals are abundantly observed in nature. To obtain the parameters of such
spirals, curve-fitting may be required. However, the usual procedure of curve-fitting fails miserably
in this regard. The difficulties become much more intense when the observed points z = (x, y) are not measured from their origin (0, 0), but shifted away from the origin by
(cx, cy). This
paper intends to devise a method to fit a logarithmic spiral to empirical data measured with a
displaced origin. The best fit has been obtained by the differential evolution method of global optimization.
© 2010 IUP. All Rights Reserved.
Effects of Injection/Suction on an Oscillatory Hydromagnetic Flow Through Porous Medium in
a Rotating Porous Channel
-- Vimal Kumar, S S Yadav and Rajeev Jha
This paper studies the effects of injection/suction on oscillatory flow of a viscous
incompressible fluid through a porous medium in a porous channel. The porous channel with constant
injection/suction, rotates about an axis perpendicular to the plates of the channel. A magnetic field
of uniform strength is also applied perpendicular to the plates. The upper plate is allowed
to oscillate in its own plane with the velocity U*(t*), while the lower plate is at rest. The effects
of Coriolis force, the magnetic field and porosity of medium on the flow are studied. The
resultant velocities R0 and R1 for the steady and unsteady parts respectively along with their phase
angles q0 and q1 have been discussed in detail.
© 2010 IUP. All Rights Reserved.
On Nearly Compact Spaces
With Respect to an Ideal
-- R Alagar and R Thenmozhy
An ideal on a set X is a non-empty collection of subsets of X with heredity property which is also closed under finite unions. The concept of nearly compact spaces was introduced by Singal
and Mathur (1969). This paper introduces nearly compact spaces with respect to an ideal and
discusses some of their properties.
© 2010 IUP. All Rights Reserved.
Magic Square Construction Algorithms
and Their Applications
-- Krishnappa H K, N K Srinath and Ramakanth Kumar P
In recreational mathematics, a magic square of order n is an arrangement of n2 numbers, usually distinct integers, in a square, such that the sum
of n numbers in all rows, all columns and
both diagonals is the same constant called the magic number. The magic square in normal is
represented using n ´ n matrix. A normal magic square contains the integers from 1 to n2. Normal magic squares exist for all
orders n ³ 1, except n = 2. The magic constant for normal magic squares
of order n is given by n(n2 + 1)/2. There are several methods for constructing the magic square of
any given order. This paper proposes algorithms to obtain the magic square of any given order n. Some of the algorithms are straight forward and others are designed using the divide and
conquer technique.
© 2010 IUP. All Rights Reserved.
Do ANNs Successfully Predict Stock Returns? Testing
its Application in Indian Stock Market
-- Renu Vashisth and Abhijeet Chandra
Artificial Neural Network (ANN) models have been proved to be powerful predictive tools, where
a variable is explained by a set of explanatory variables without assuming any structural or
linear relationship among the variables. In the field of finance, a large number of models, especially
those derived from the field of econometrics, are used for forecasting stock returns. This paper intends
to test the forecasting ability of ANN models using Nifty index data from Indian stock market.
Daily time series data of the index of National Stock Exchange is analyzed using a three-layer
architecture of the ANN. The results of the study reveal that ANN models could efficiently predict daily
returns of Nifty index for a given period under investigation. The results of this study are significant
value addition to the trading decisions in the stock index futures with special reference to Indian
stock market.
© 2010 IUP. All Rights Reserved.
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September '10
